Yes, it is possible to only activate Reserve with Instagram without Reserve with Facebook. You will need a workaround for that.

Activate Reserve with Instagram AND Reserve with Facebook on a Facebook Page of your choice. Then unpublish the Facebook page. Reservations will then be possible only via Instagram. If you don’t a Facebook Page you can unpublish, simply create a new Facebook Page. 

To do this work around, first make sure you have:  

• A Facebook Account  
• A Facebook Page on which you can activate "Reserve with Facebook" 
• Be willing to unpublish this Facebook Page  

1) Activate "Reserve with Facebook" and "Reserve with Instagram"  

1. Go to Settings/Reservations in DISH Reservation. 
2. Click Activate Now on the “Reserve with Facebook” section. 
3. A pop-up window opens. Read and click Activate now. 
4. A Facebook pop-up opens. Log in and follow the steps. 
5. Select a Facebook Page (the one that you will then unpublish).  
6. Select your Instagram Page. 
7. Select an Ad and Meta Pixel Account (usually pre-set). 
8. Click on Continue. 
9. Give permission to Mozrest to Manage business Extension and Click Next. 
10. Click Done and close the window. 
11. Go back to DISH Reservation, view the pop-up and click on Finish Setup.  

2) Unpublish your Facebook Page 

• Follow the steps in the guide on how to "Unpublish or deactivate your Facebook Page": https://www.facebook.com/help/184605634921611  

Congratulations! You should now only receive reservations via Instagram.